No abstract

In this work, efforts were taken to investigate the free convection of ethylene glycol-based Casson nanofluid and it is affected by a magnetic field about a horizontal circular cylinder. Three different types of oxide nanoparticles were used along with constant wall temperature. Tiwari and Das's nanofluid model was used to investigate the MHD free convective flow of Casson nanofluid. The transformed governing PDEs were solved via the Keller box method. Numerical and graphical findings were acquired by using MATLAB software, in addition to studying and analyzing the influence of related parameters, on the velocity, temperature, local skin friction coefficient, and local Nusselt number. The results demonstrate that copper oxide ethylene glycol-based Casson nanofluid has the lowest local Nusselt number, velocity and, it has the highest temperature. Also, our results were in excellent agreement with prior published results.

This numerical investigation intends to present the impact of nanoparticles volume fraction, Casson, and magnetic force on natural convection in the boundary layer region of a horizontal cylinder in a Casson nanofluid under constant heat flux boundary conditions. Methanol is considered as a host Casson fluid. Graphite oxide (GO), single and multiple walls carbon nanotubes (SWCNTs and MWCNTs) nanoparticles have been incorporated to support the heat transfer performances of the host fluid. The Keller box technique is employed to solve the transformed governing equations. Our numerical findings were in an excellent agreement with the preceding literature. Graphical results of the effect of the relevant parameters on some physical quantities related to examine the behavior of Casson nanofluid flow were obtained, and they confirmed that an augmentation in Casson parameter results in a decline in local skin friction, velocity, or temperature, as well as leading to an increment in local Nusselt number. Furthermore, MWCNTs are the most efficient in improving the rate of heat transfer and velocity, and they possess the lowest temperature.

The heat transfer of a carboxymethyl cellulose aqueous solution (CMC-water) based Casson nanofluid, flowing under the impact of a variable-strength magnetic field in mixed convection around a solid sphere, has been examined in this work. Aluminum (Al), copper (Cu), and silver (Ag) nanoparticles were employed to support the heat transfer characteristics of the host fluid. A numerical approach called the Keller-box method (KBM) was used to solve the governing system for the present problem, and also to examine and analyze the numerical and graphic results obtained by the MATLAB program, verifying their accuracy through comparing them with the prior literature. The results demonstrate that a Al–CMC-water nanoliquid is superior in terms of heat transfer rate and skin friction. The velocity of CMC-water is higher with Ag compared to Al–CMC-water, and Ag–CMC-water possesses the lowest temperature. Growing mixed parameter values result in a rising skin friction, velocity and Nusselt number or decline in temperature.

This work aimed to establish a numerical simulation of kerosene oil as a host Casson fluid flowing around a cylindrical shape with an applied magnetic field crossing through it, under constant wall temperature boundary conditions. Nanoparticles of zinc, aluminum, and titanium oxides were included to reinforce its thermal characteristics. The governing model was established based on the Tiwari and Das model. Graphical and numerical results for correlated physical quantities were gained through the Keller Box method, with the assistance of MATLAB software (9.2). The combined convection (λ>0 & λ<0), magnetic parameter (M>0), Casson parameter (β>0), and nanosolid volume fraction (0.1≤χ≤0.2) were the parameter ranges considered in this study. According to the current findings, the growth of mixed convection parameter or volume fraction of ultrafine particles contributes to boosting the rate of energy transport, skin friction, and velocity distribution. Zinc oxide–kerosene oil has the highest velocity and temperature, whatever the parameters influencing it.

In this paper, we examined a free convection flow of Sodium Alginate (SA) as a host Casson fluid with three different types of nanoparticles specifically, Silicon Dioxide (SiO2), Copper oxide (CuO), and Copper (Cu) on a solid sphere in the presence of magnetic field along with prescribed surface heat flux. The Keller-box method was carried out for solving the transformed governing partial differential equations. Numerical results for the local skin friction coefficient are obtained and compared with literature. Also, the influences of Casson parameter, magnetic parameter, nanoparticles volume fraction, on local skin friction coefficient, local Nusselt number, temperature, and velocity are analyzed graphically. Our study revealed that the local Nusselt number, local skin friction coefficient and velocity profiles of SiO2 - SA based Casson nanofluid are higher than the other nanoparticles - SA based Casson nanofluid, as well as it has the lowest temperature profiles.

The assumptions that form our focus in this study are water or water-ethylene glycol flowing around a horizontal cylinder, containing hybrid nanoparticles, affected by a magnetic force, and under a constant wall temperature, in addition to considering free convection. The Tiwari–Das model is employed to highlight the influence of the nanoparticles volume fraction on the flow characteristics. A numerical approximate technique called the Keller box method is implemented to obtain a solution to the physical model. The effects of some critical parameters related to heat transmission are also graphically examined and analyzed. The increase in the nanoparticle volume fraction increases the heat transfer rate and liquid velocity; the strength of the magnetic field has an adverse effect on liquid velocity, heat transfer, and skin friction. We find that cobalt nanoparticles provide more efficient support for the heat transfer rate of aluminum oxide than aluminum nanoparticles.

This paper investigates hybrid nanofluids flowing around a circular cylinder of free convection under the constant surface heat flux.  Nanoparticles of copper oxides, Gold, and Aluminum (CuO, Au, Al) are considered to support the heat transfer performance of blood/water-based hybrid nanofluids. The governing model for hybrid nanofluids which is in form of non-linear partial differential equations (PDEs) are first transformed to a more convenient form by similarity transformation approach then approximated numerically by the Keller box method. Several comparatives are performed in this work resulting in the superiority of the hybrid-nanofluid over regular nanofluid in terms of heat transfer rate, velocity, and local skin friction coefficient.  Findings confirmed that the surface temperature and temperature field are augmented, with increasing volume fraction for nanoparticles. Also, Gold nanoparticles give a higher result for all examined physical properties than Aluminum and copper oxides nanoparticles.